/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#if SDL_VIDEO_RENDER_OGL

#include "SDL_video.h"

#include "SDL_opengl.h"

#include "SDL_sysvideo.h"

#include "SDL_pixels_c.h"

#include "SDL_rect_c.h"

#include "SDL_yuv_sw_c.h"

#ifdef __MACOSX__

#include <OpenGL/OpenGL.h>

#endif

/* OpenGL renderer implementation */

/* Details on optimizing the texture path on Mac OS X:

   http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_texturedata/chapter_10_section_2.html

*/

/* !!! FIXME: this should go in a higher level than the GL renderer. */

static __inline__ int

bytes_per_pixel(const Uint32 format)

{

    if (!SDL_ISPIXELFORMAT_FOURCC(format)) {

        return SDL_BYTESPERPIXEL(format);

    }

    /* FOURCC format */

    switch (format) {

        case SDL_PIXELFORMAT_YV12:

        case SDL_PIXELFORMAT_IYUV:

        case SDL_PIXELFORMAT_YUY2:

        case SDL_PIXELFORMAT_UYVY:

        case SDL_PIXELFORMAT_YVYU:

            return 2;

        default:

            return 1;  /* shouldn't ever hit this. */

    }

}

static const float inv255f = 1.0f / 255.0f;

static SDL_Renderer *GL_CreateRenderer(SDL_Window * window, Uint32 flags);

static int GL_ActivateRenderer(SDL_Renderer * renderer);

static int GL_DisplayModeChanged(SDL_Renderer * renderer);

static int GL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static int GL_QueryTexturePixels(SDL_Renderer * renderer,

                                 SDL_Texture * texture, void **pixels,

                                 int *pitch);

static int GL_SetTexturePalette(SDL_Renderer * renderer,

                                SDL_Texture * texture,

                                const SDL_Color * colors, int firstcolor,

                                int ncolors);

static int GL_GetTexturePalette(SDL_Renderer * renderer,

                                SDL_Texture * texture, SDL_Color * colors,

                                int firstcolor, int ncolors);

static int GL_SetTextureColorMod(SDL_Renderer * renderer,

                                 SDL_Texture * texture);

static int GL_SetTextureAlphaMod(SDL_Renderer * renderer,

                                 SDL_Texture * texture);

static int GL_SetTextureBlendMode(SDL_Renderer * renderer,

                                  SDL_Texture * texture);

static int GL_SetTextureScaleMode(SDL_Renderer * renderer,

                                  SDL_Texture * texture);

static int GL_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                            const SDL_Rect * rect, const void *pixels,

                            int pitch);

static int GL_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                          const SDL_Rect * rect, int markDirty, void **pixels,

                          int *pitch);

static void GL_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static void GL_DirtyTexture(SDL_Renderer * renderer, SDL_Texture * texture,

                            int numrects, const SDL_Rect * rects);

static int GL_RenderFill(SDL_Renderer * renderer, Uint8 r, Uint8 g, Uint8 b,

                         Uint8 a, const SDL_Rect * rect);

static int GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,

                         const SDL_Rect * srcrect, const SDL_Rect * dstrect);

static void GL_RenderPresent(SDL_Renderer * renderer);

static void GL_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static void GL_DestroyRenderer(SDL_Renderer * renderer);

SDL_RenderDriver GL_RenderDriver = {

    GL_CreateRenderer,

    {

     "opengl",

     (SDL_RENDERER_SINGLEBUFFER | SDL_RENDERER_PRESENTDISCARD |

      SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED),

     (SDL_TEXTUREMODULATE_NONE | SDL_TEXTUREMODULATE_COLOR |

      SDL_TEXTUREMODULATE_ALPHA),

     (SDL_TEXTUREBLENDMODE_NONE | SDL_TEXTUREBLENDMODE_MASK |

      SDL_TEXTUREBLENDMODE_BLEND | SDL_TEXTUREBLENDMODE_ADD |

      SDL_TEXTUREBLENDMODE_MOD),

     (SDL_TEXTURESCALEMODE_NONE | SDL_TEXTURESCALEMODE_FAST |

      SDL_TEXTURESCALEMODE_SLOW),

     15,

     {

      SDL_PIXELFORMAT_INDEX1LSB,

      SDL_PIXELFORMAT_INDEX1MSB,

      SDL_PIXELFORMAT_INDEX8,

      SDL_PIXELFORMAT_RGB332,

      SDL_PIXELFORMAT_RGB444,

      SDL_PIXELFORMAT_RGB555,

      SDL_PIXELFORMAT_ARGB4444,

      SDL_PIXELFORMAT_ARGB1555,

      SDL_PIXELFORMAT_RGB565,

      SDL_PIXELFORMAT_RGB24,

      SDL_PIXELFORMAT_BGR24,

      SDL_PIXELFORMAT_RGB888,

      SDL_PIXELFORMAT_BGR888,

      SDL_PIXELFORMAT_ARGB8888,

      SDL_PIXELFORMAT_ABGR8888,

      SDL_PIXELFORMAT_ARGB2101010},

     0,

     0}

};

typedef struct

{

    SDL_GLContext context;

    SDL_bool updateSize;

    SDL_bool GL_ARB_texture_rectangle_supported;

    SDL_bool GL_EXT_paletted_texture_supported;

    SDL_bool GL_ARB_fragment_program_supported;

    int blendMode;

    int scaleMode;

    /* OpenGL functions */

#define SDL_PROC(ret,func,params) ret (APIENTRY *func) params;

#include "SDL_glfuncs.h"

#undef SDL_PROC

    PFNGLCOLORTABLEEXTPROC glColorTableEXT;

    void (*glTextureRangeAPPLE) (GLenum target, GLsizei length,

                                 const GLvoid * pointer);

    PFNGLGETPROGRAMIVARBPROC glGetProgramivARB;

    PFNGLGETPROGRAMSTRINGARBPROC glGetProgramStringARB;

    PFNGLPROGRAMLOCALPARAMETER4FVARBPROC glProgramLocalParameter4fvARB;

    PFNGLDELETEPROGRAMSARBPROC glDeleteProgramsARB;

    PFNGLGENPROGRAMSARBPROC glGenProgramsARB;

    PFNGLBINDPROGRAMARBPROC glBindProgramARB;

    PFNGLPROGRAMSTRINGARBPROC glProgramStringARB;

    /* (optional) fragment programs */

    GLuint fragment_program_UYVY;

} GL_RenderData;

typedef struct

{

    GLuint texture;

    GLuint shader;

    GLenum type;

    GLfloat texw;

    GLfloat texh;

    GLenum format;

    GLenum formattype;

    Uint8 *palette;

    void *pixels;

    int pitch;

    SDL_DirtyRectList dirty;

int HACK_RYAN_FIXME;

} GL_TextureData;

static void

GL_SetError(const char *prefix, GLenum result)

{

    const char *error;

    switch (result) {

    case GL_NO_ERROR:

        error = "GL_NO_ERROR";

        break;

    case GL_INVALID_ENUM:

        error = "GL_INVALID_ENUM";

        break;

    case GL_INVALID_VALUE:

        error = "GL_INVALID_VALUE";

        break;

    case GL_INVALID_OPERATION:

        error = "GL_INVALID_OPERATION";

        break;

    case GL_STACK_OVERFLOW:

        error = "GL_STACK_OVERFLOW";

        break;

    case GL_STACK_UNDERFLOW:

        error = "GL_STACK_UNDERFLOW";

        break;

    case GL_OUT_OF_MEMORY:

        error = "GL_OUT_OF_MEMORY";

        break;

    case GL_TABLE_TOO_LARGE:

        error = "GL_TABLE_TOO_LARGE";

        break;

    default:

        error = "UNKNOWN";

        break;

    }

    SDL_SetError("%s: %s", prefix, error);

}

static int

GL_LoadFunctions(GL_RenderData * data)

{

#if defined(__QNXNTO__) && (_NTO_VERSION < 630)

#define __SDL_NOGETPROCADDR__

#elif defined(__MINT__)

#define __SDL_NOGETPROCADDR__

#endif

#ifdef __SDL_NOGETPROCADDR__

#define SDL_PROC(ret,func,params) data->func=func;

#else

#define SDL_PROC(ret,func,params) \

    do { \

        data->func = SDL_GL_GetProcAddress(#func); \

        if ( ! data->func ) { \

            SDL_SetError("Couldn't load GL function %s: %s\n", #func, SDL_GetError()); \

            return -1; \

        } \

    } while ( 0 );

#endif /* __SDL_NOGETPROCADDR__ */

#include "SDL_glfuncs.h"

#undef SDL_PROC

    return 0;

}

void

GL_AddRenderDriver(_THIS)

{

    if (_this->GL_CreateContext) {

        SDL_AddRenderDriver(0, &GL_RenderDriver);

    }

}

SDL_Renderer *

GL_CreateRenderer(SDL_Window * window, Uint32 flags)

{

    SDL_Renderer *renderer;

    GL_RenderData *data;

    GLint value;

    int doublebuffer;

    /* Render directly to the window, unless we're compositing */

#ifndef __MACOSX__

    if (flags & SDL_RENDERER_SINGLEBUFFER) {

        SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 0);

    }

#endif

    if (!(window->flags & SDL_WINDOW_OPENGL)) {

        if (SDL_RecreateWindow(window, window->flags | SDL_WINDOW_OPENGL) < 0) {

            return NULL;

        }

    }

    renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));

    if (!renderer) {

        SDL_OutOfMemory();

        return NULL;

    }

    data = (GL_RenderData *) SDL_calloc(1, sizeof(*data));

    if (!data) {

        GL_DestroyRenderer(renderer);

        SDL_OutOfMemory();

        return NULL;

    }

    renderer->ActivateRenderer = GL_ActivateRenderer;

    renderer->DisplayModeChanged = GL_DisplayModeChanged;

    renderer->CreateTexture = GL_CreateTexture;

    renderer->QueryTexturePixels = GL_QueryTexturePixels;

    renderer->SetTexturePalette = GL_SetTexturePalette;

    renderer->GetTexturePalette = GL_GetTexturePalette;

    renderer->SetTextureColorMod = GL_SetTextureColorMod;

    renderer->SetTextureAlphaMod = GL_SetTextureAlphaMod;

    renderer->SetTextureBlendMode = GL_SetTextureBlendMode;

    renderer->SetTextureScaleMode = GL_SetTextureScaleMode;

    renderer->UpdateTexture = GL_UpdateTexture;

    renderer->LockTexture = GL_LockTexture;

    renderer->UnlockTexture = GL_UnlockTexture;

    renderer->DirtyTexture = GL_DirtyTexture;

    renderer->RenderFill = GL_RenderFill;

    renderer->RenderCopy = GL_RenderCopy;

    renderer->RenderPresent = GL_RenderPresent;

    renderer->DestroyTexture = GL_DestroyTexture;

    renderer->DestroyRenderer = GL_DestroyRenderer;

    renderer->info = GL_RenderDriver.info;

    renderer->window = window->id;

    renderer->driverdata = data;

    renderer->info.flags =

        (SDL_RENDERER_PRESENTDISCARD | SDL_RENDERER_ACCELERATED);

    if (GL_LoadFunctions(data) < 0) {

        GL_DestroyRenderer(renderer);

        return NULL;

    }

    data->context = SDL_GL_CreateContext(window->id);

    if (!data->context) {

        GL_DestroyRenderer(renderer);

        return NULL;

    }

    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {

        GL_DestroyRenderer(renderer);

        return NULL;

    }

#ifdef __MACOSX__

    /* Enable multi-threaded rendering */

    /* Disabled until Ryan finishes his VBO/PBO code...

       CGLEnable(CGLGetCurrentContext(), kCGLCEMPEngine);

     */

#endif

    if (flags & SDL_RENDERER_PRESENTVSYNC) {

        SDL_GL_SetSwapInterval(1);

    } else {

        SDL_GL_SetSwapInterval(0);

    }

    if (SDL_GL_GetSwapInterval() > 0) {

        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;

    }

    if (SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &doublebuffer) == 0) {

        if (!doublebuffer) {

            renderer->info.flags |= SDL_RENDERER_SINGLEBUFFER;

        }

    }

    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);

    renderer->info.max_texture_width = value;

    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);

    renderer->info.max_texture_height = value;

    if (SDL_GL_ExtensionSupported("GL_ARB_texture_rectangle")

        || SDL_GL_ExtensionSupported("GL_EXT_texture_rectangle")) {

        data->GL_ARB_texture_rectangle_supported = SDL_TRUE;

    }

    if (SDL_GL_ExtensionSupported("GL_EXT_paletted_texture")) {

        data->GL_EXT_paletted_texture_supported = SDL_TRUE;

        data->glColorTableEXT =

            (PFNGLCOLORTABLEEXTPROC) SDL_GL_GetProcAddress("glColorTableEXT");

    } else {

        /* Don't advertise support for 8-bit indexed texture format */

        Uint32 i, j;

        SDL_RendererInfo *info = &renderer->info;

        for (i = 0, j = 0; i < info->num_texture_formats; ++i) {

            if (info->texture_formats[i] != SDL_PIXELFORMAT_INDEX8) {

                info->texture_formats[j++] = info->texture_formats[i];

            }

        }

        --info->num_texture_formats;

    }

    if (SDL_GL_ExtensionSupported("GL_APPLE_texture_range")) {

        data->glTextureRangeAPPLE =

            (void (*)(GLenum, GLsizei, const GLvoid *))

            SDL_GL_GetProcAddress("glTextureRangeAPPLE");

    }

    /* we might use fragment programs for YUV data, etc. */

    if (SDL_GL_ExtensionSupported("GL_ARB_fragment_program")) {

        /* !!! FIXME: this doesn't check for errors. */

        /* !!! FIXME: this should really reuse the glfuncs.h stuff. */

        data->glGetProgramivARB = (PFNGLGETPROGRAMIVARBPROC)

            SDL_GL_GetProcAddress("glGetProgramivARB");

        data->glGetProgramStringARB = (PFNGLGETPROGRAMSTRINGARBPROC)

            SDL_GL_GetProcAddress("glGetProgramStringARB");

        data->glProgramLocalParameter4fvARB =

            (PFNGLPROGRAMLOCALPARAMETER4FVARBPROC)

            SDL_GL_GetProcAddress("glProgramLocalParameter4fvARB");

        data->glDeleteProgramsARB = (PFNGLDELETEPROGRAMSARBPROC)

            SDL_GL_GetProcAddress("glDeleteProgramsARB");

        data->glGenProgramsARB = (PFNGLGENPROGRAMSARBPROC)

            SDL_GL_GetProcAddress("glGenProgramsARB");

        data->glBindProgramARB = (PFNGLBINDPROGRAMARBPROC)

            SDL_GL_GetProcAddress("glBindProgramARB");

        data->glProgramStringARB = (PFNGLPROGRAMSTRINGARBPROC)

            SDL_GL_GetProcAddress("glProgramStringARB");

        data->GL_ARB_fragment_program_supported = SDL_TRUE;

    }

    /* Set up parameters for rendering */

    data->blendMode = -1;

    data->scaleMode = -1;

    data->glDisable(GL_DEPTH_TEST);

    data->glDisable(GL_CULL_FACE);

    if (data->GL_ARB_texture_rectangle_supported) {

        data->glEnable(GL_TEXTURE_RECTANGLE_ARB);

    } else {

        data->glEnable(GL_TEXTURE_2D);

    }

    data->updateSize = SDL_TRUE;

    return renderer;

}

static int

GL_ActivateRenderer(SDL_Renderer * renderer)

{

    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;

    SDL_Window *window = SDL_GetWindowFromID(renderer->window);

    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {

        return -1;

    }

    if (data->updateSize) {

        data->glMatrixMode(GL_PROJECTION);

        data->glLoadIdentity();

        data->glMatrixMode(GL_MODELVIEW);

        data->glLoadIdentity();

        data->glViewport(0, 0, window->w, window->h);

        data->glOrtho(0.0, (GLdouble) window->w, (GLdouble) window->h, 0.0,

                      0.0, 1.0);

        data->updateSize = SDL_FALSE;

    }

    return 0;

}

static int

GL_DisplayModeChanged(SDL_Renderer * renderer)

{

    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;

    /* Rebind the context to the window area and update matrices */

    data->updateSize = SDL_TRUE;

    return GL_ActivateRenderer(renderer);

}

static __inline__ int

power_of_2(int input)

{

    int value = 1;

    while (value < input) {

        value <<= 1;

    }

    return value;

}

#define DEBUG_PROGRAM_COMPILE 1

static GLuint

compile_shader(GL_RenderData *data, GLenum shader_type, const char *source)

{

#if DEBUG_PROGRAM_COMPILE

    printf("compiling shader:\n%s\n\n", source);

#endif

    GLuint program = 0;

    data->glGetError();  /* flush any existing error state. */

    data->glGenProgramsARB(1, &program);

    data->glBindProgramARB(shader_type, program);

    data->glProgramStringARB(shader_type, GL_PROGRAM_FORMAT_ASCII_ARB,

                             SDL_strlen(source), source);

    if (data->glGetError() == GL_INVALID_OPERATION)

    { 

#if DEBUG_PROGRAM_COMPILE

        GLint pos = 0;

        const GLubyte *errstr;

        data->glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &pos);

        errstr = data->glGetString(GL_PROGRAM_ERROR_STRING_ARB);

        printf("program compile error at position %d: %s\n\n",

                  (int) pos, (const char *) errstr);

#endif

        data->glBindProgramARB(shader_type, 0);

        data->glDeleteProgramsARB(1, &program);

        return 0;